#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main() {
    long int n;
    int i, j, time;
    scanf("%ld", &n);
    if (n >= 12)
    {
        i = (n /= 12);
        time = i * 4 + 2;
        printf("%d", time);
    }
    else
    {
        printf("%d", 2);
    }
    return 0;
}